Light stick



FIG. 1 is a perspective view of the light stick;

FIG. 2 is a top view of the light stick;

FIG. 3 is a bottom view of the light stick;

FIG. 4 is a front view of the light stick; and,

FIG. 5 is a side view of the light stick.

The broken line showing of the stick portion is included for the purpose of illustrating the stick portion and forms no part of the claimed design. 

The ornamental design for a light stick, as shown and described. 